> I am new to glpk and MathProg. I am trying to model a problem in glpk > and solve it. The problem is that I don’t know how should I define the > following : > We have E[i] for each i that is member of N : > N is a set that contains A B C D E, > So, we have E[A], E[B], E[C], E[D], E[E] > The value for each of these members is as follows, for example: > E[A]:= AB > E[B] := AB BC > E[C] := BC CD > E[D] := CD DE > E[E] := DE > The problem is that I don’t know how to define E with the above > specifications!
> I have tested the followings and it didn’t work: > 1) > param E:= > A AB; > B AB BC > C BC CD > D CD DE > E DE; > 2) > param E : > if i==A > then AB > else if i==B > then AB BC > else if i==C > then BC CD > else if i==D > then CD DE > else if i==E > then DE; > 3) > set EA; /*set of edges connected to node A*/ > set EB; /*set of edges connected to node B*/ > set EC; /*set of edges connected to node C*/ > set ED; /*set of edges connected to node D*/ > set EE; /*set of edges connected to node E*/ > set EA := AB; > set EB := AB BC; > set EC := BC CD; > set ED := CD DE; > set EE := DE; > and also we have: > u can be AB BC CD DE > and after defining the E, I have to check something like this: > for each I in N, for each u that is in E[i] ….some condition…… > I really don’t know how should I solve this problem,how to define E, > and it is very essential to solve this problem.. > Please do me a favor and help! > Many thanks in advance. You may try something like this: set N; set E{i in N}, dimen 2; display E; data; set N := A B C D E; set E[A] := (A,B); set E[B] := (A,B) (B,C); set E[C] := (B,C) (C,D); set E[D] := (C,D) (D,E); set E[E] := (D,E); _______________________________________________ Help-glpk mailing list Help-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/help-glpk